The present invention relates to a rolling mill of the type in which a work roll is offset by a predetermined distance from the reduction line and the horizontal bending force is exerted to the work roll through a horizontal intermediate roll from a sectionalized roll, whereby flatness of a workpiece being rolled can be controlled.
In order to improve the quality of rolled products, work rolls are bent so as to control the flatness of a workpiece being rolled. There has been devised and demonstrated a rolling mill of the type in which a small-diameter work roll is used and is offset by a predetermined distance from the reduction line and the horizontal bending force is exerted to the small-diameter work roll so as to control the flatness of a workpiece being rolled.
A horizontal bending device for exerting the horizontal bending force to the small-diameter work roll as described above comprises in general a horizontal intermediate roll adapted to transmit the horizontal bending force to the small-diameter work roll and a sectionalized roll adapted to exert the bending force to the horizontal intermediate roll. In order to correctly transmit the bending force from the sectionalized roll to the small-diameter work roll, the axes of the small-diameter work roll, horizontal intermediate roll and sectionalized roll must be maintained in coplanar relationship with each other.
The centering or alignment of the axes of the small-diameter work roll, horizontal intermediate roll and sectionalized roll is effected when each of them is assembled into the rolling mill. Alternatively, a small-diameter work roll and a horizontal intermediate roll are assembled as a unitary construction and the alignment of its axis with the axis of the sectionalized roll is effected. As a result, after they have been assembled into the rolling mill and when the rolling mill is operating, the fine alignment of their axes is not made so that the accuracy in alignment is poor. When a small-diameter work roll is ground for re-use, its diameter changes so that the re-alignment is needed. This re-alignment operation is very troublesome. Furthermore, there is a disadvantage that due to the variation in diameter of a small-diameter work roll, the pass line is changed.